shiroka
112 lines
3.7 KiB
C++
112 lines
3.7 KiB
C++
// Geant4 simulation for MuSR
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// AUTHOR: Toni SHIROKA, Paul Scherrer Institut, PSI
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// DATE : 2008-05
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//
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//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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// Muonium Formation according to yield.cc function (through GetYields method).
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// Id : lem4MuFormation.cc, v 1.4
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// Author: Taofiq PARAISO, T. Shiroka
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// Date : 2007-12
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//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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#include "lem4MuFormation.hh"
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using namespace std;
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lem4MuFormation::lem4MuFormation(const G4String& name, G4ProcessType aType)
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: G4VDiscreteProcess(name, aType){}
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lem4MuFormation::~lem4MuFormation(){}
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G4VParticleChange* lem4MuFormation::PostStepDoIt(const G4Track& trackData,
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const G4Step& aStep)
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{ // Initialize ParticleChange (by setting all its members equal to
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// the corresponding members in G4Track)
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fParticleChange.Initialize(trackData);
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G4Track theNewTrack;
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if(CheckCondition(aStep))
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{
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GetDatas(&aStep);
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G4Step theStep;
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PrepareSecondary( trackData);
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fParticleChange.AddSecondary(aSecondary);
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fParticleChange.ProposeTrackStatus(fStopAndKill) ;
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}
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else
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{
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fParticleChange.ProposeTrackStatus(trackData.GetTrackStatus()) ;
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}
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return &fParticleChange;
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}
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G4bool lem4MuFormation::CheckCondition(const G4Step& aStep)
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{ // Decide when to call the MuFormation process - i.e. for muons going through the C foil.
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G4bool condition=false;
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p_name = aStep.GetTrack()->GetDefinition()->GetParticleName(); // particle name
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//if(p_name == "mu+"&&aStep.GetTrack()->GetVolume()->GetLogicalVolume()->GetName()=="log_CFoil")
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std::string logVolName = aStep.GetTrack()->GetVolume()->GetLogicalVolume()->GetName();
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if(p_name == "mu+" && ((logVolName=="log_coulombCFoil")||(logVolName=="log_CFoil")))
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{
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condition=true;
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}
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return condition;
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}
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G4double lem4MuFormation::GetMeanFreePath(const G4Track&,
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G4double,
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G4ForceCondition* condition)
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{
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*condition = Forced;
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return DBL_MAX;
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}
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void lem4MuFormation::GetDatas(const G4Step* aStep)
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{ // Particle generation according to yield table
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particleTable=G4ParticleTable::GetParticleTable();
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rnd=G4UniformRand();
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G4double E = aStep->GetTrack()->GetDynamicParticle()->GetKineticEnergy()/keV;
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Gonin.GetYields(E,105.658369*1000,yvector); // Energy [keV], muon mass [keV/c2], yield table
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G4String p_new = "Mu";
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// Positive muon
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if(p_name=="mu+")
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{
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if(rnd<yvector[0])
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{
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particle = particleTable->FindParticle(p_name) ;
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}
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else
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{
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particle = particleTable->FindParticle(p_new);
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}
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// Set the new dynamic particle DP
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DP = new G4DynamicParticle(particle,
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aStep->GetTrack()->GetDynamicParticle()->GetMomentumDirection(),
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aStep->GetTrack()->GetDynamicParticle()->GetKineticEnergy());
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// IMPORTANT : COPY THOSE DATA TO GET THE SAME PARTICLE PROPERTIES!!!
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// SHOULD BE KEPT WHEN BUILDING A PARTICLE CHANGE
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DP->SetProperTime( aStep->GetTrack()->GetDynamicParticle()->GetProperTime());
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DP->SetPolarization(aStep->GetTrack()->GetDynamicParticle()->GetPolarization().x(),
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aStep->GetTrack()->GetDynamicParticle()->GetPolarization().y(),
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aStep->GetTrack()->GetDynamicParticle()->GetPolarization().z());
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DP->SetPreAssignedDecayProperTime(aStep->GetTrack()->GetDynamicParticle()->GetPreAssignedDecayProperTime());
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}
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}
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void lem4MuFormation::PrepareSecondary(const G4Track& track)
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{
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if(p_name=="mu+")
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{
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aSecondary = new G4Track(DP,track.GetGlobalTime(),track.GetPosition());
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}
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}
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